What Causes Bleeding In Vagina After Fingering?

I'm a virgin but my vagina bleeds after fingering myself. I have been doing so for a long time over 3 years now and the first year it didn't bleed but after that first year passed I started to finger myself harder as it got me off quicker and felt better. For about a year now I bleed everytime I finger myself relatively hard or deep. The only times I don't bleed is when I don't push my fingers deep enough or hard enough. Should this be something I should be worried about? Is this normal and what should I do to help cure this bleeding?